#### Answer

9 inches

#### Work Step by Step

First, convert all distances in the question to inches for easy calculations: ( 1ft = 12 inches, multiply all ft by 12 to get the same distance in inches)
14ft 6 in = 174 inches
2 ft 6 in = 30 inches
1 ft = 12 inches
First, find the total distance between the two windows:
There are 4 windows, each window is 2ft 6 in (30 inches)
Total distance of all windows= $ 30\times 4=120 $ inches
There are 3 gaps between the 4 windows, each gap being 1 ft wide (12 inches)
Total distance of all gaps = $3\times 12=36$inches
Total distance between the two windows = 36 + 120 = 156 inches
Next, we can find the space between the walls and windows by deducting 156 inches from the total length of the two walls (174 inches):
174-156=18 inches
Since there are two spaces between the wall and the window, next to the right inside wall and next to the left inside wall, divide the above value by two to obtain the distance for just one space.
$18\div2=9$inches